I just replaced my control board and main board on a 96 d1 spa. It came on for about 10 seconds then came up with a OH and then went dead. The only thing that works is the light on the cotroller. The air pump barley hums too. It appears to be the main time delay fuse. So I am wondering if the fuse just happened to blow or could something be shorting it out? I have an slc 30a fuse. Should I just replace it and try it? I dont want to damage my new board or controller.

Another thing I am pretty sure it never got hot for the OH to show up considering it was only on for 10 seconds and it wasnt very warm when I felt it right afterwards.

I found a tester and tested my fuse. It was good so I put it back in and somehow everything works.